Hot Shower Kit 2.0 - with Autoherm Heater + combiBOIL with Comfort Boiler Control

Hot Shower Kit 2.0

The Hot Shower Kit is the easy way to equip expedition vehicles or boat & yacht with a warm-air heater and hot water at the same time. Compared to technically complex combo units, the kit uses two separate devices, making it more affordable and, above all, less prone to total system failure. And if necessary, it can even be repaired while on the road.

The strength of the Hot Shower Kit lies in its simplicity and in the fact that the two main elements (heater and boiler) operate independently. A fault in one component does not automatically affect the other. A defect in the boiler is unlikely thanks to the high material and manufacturing quality with great pressure resistance – but should damage occur for whatever reason, the heater keeps running completely unfazed, and that’s a very good thing. Not being able to take a hot shower is one thing – spending the night in a completely cooled-down vehicle at perhaps −20 °C is quite another.

The Hot Shower Kit 2.0 is therefore a simple, easy-to-install system. It’s perfect for DIY builders, but of course also for professional manufacturers who want to offer their customers a low-maintenance, reliable solution for their travels.

How does the Hot Shower Kit 2.0 work

The Hot Shower Kit 2.0 can produce hot water in three different ways:

• Via an electric heating element, i.e. using shore power or your battery reserves when there’s plenty of energy available.
• Simply on the side while the heater is running – without consuming any additional energy. Hot water is essentially the „byproduct“.
• New: The boiler can be integrated into the engine’s coolant circuit to heat either the domestic water itself or a second hydronic loop.

Each of these three options has its advantages and can be used whenever it suits best. After a few days of off-grid camping in hot weather, for example, you probably don’t want to run the heater, nor is the water warmed by driving. But if it’s too warm to run the heater, you likely have solar yield, meaning enough battery power to generate hot water via the electric heating element.

With the combination of three options, this kit always offers the one that fits perfectly in any situation.

The options for integrating into the coolant circuit are as follows:

• Coolant circuit heats domestic water: The engine coolant circuit is connected to the boiler and heats domestic water for the shower, etc., while driving. Caution: Because coolant temperatures can exceed 100 °C due to pressure, overheating of the boiler must be prevented by a valve or by switching off the circulation pump!
• Boiler preheats the coolant circuit (engine): The reverse of the above. By connecting the boiler to a 230 V/110 V power source or using warm air from the air heater, the engine’s coolant circuit can be preheated.
• Heating a second hydronic loop: The energy introduced into the boiler via the electric heating element or warm air is transferred by a circulation pump into a second water circuit. Merging both water circuits (so that the coolant circuit heats the second loop) is also possible; in this case, precautions regarding the engine’s supply temperature must be taken.

New: Integration of a second hydronic loop

With combiBOIL it’s possible to operate a second water loop with hot water. This allows, for example, underfloor heating or towel radiators so you can dry wet clothes and towels more easily inside the vehicle.

Note that this requires an expansion vessel to be integrated into the loop and the water may need to be circulated by a circulation pump, depending on the application.

About the term „underfloor heating“

The underfloor heating with the Hot Shower Kit is not intended to heat the room volume as in a house. The energy won’t be sufficient for that. But if you lay, for example, 2–3 m² of heating loop in the seating area, cold feet and the unpleasant feeling of a cold vehicle floor are a thing of the past, and the warmth from below creates a completely different feel-good atmosphere in your camper.
 

What you get with the Hot Shower Kit 2.0

The Hot Shower Kit 2.0 consists of two main components (heater and boiler) plus the materials to connect and install them so they work together as a perfectly matched system.
 

The heater

The diesel air heaters from Autoterm, specifically the two models used here – Air 2D and Air 4D – have become indispensable in expedition vehicles, boats and yachts. For many years, these robust units from the Latvian manufacturer have proven themselves and enjoy an excellent reputation.

Important for DIY builders: Installation may be carried out by non-professionals without voiding the warranty (provided the included manufacturer installation notes are followed! In case of damage, the seller must check the case and Autoterm must be notified). The heaters also carry an E-mark certification, which means the installation does not need to be registered with TÜV.

Autoterm heaters are fuel-efficient and quiet in operation. For even lower noise levels, see our separately available Schlafgut warm-air silencer (article no. 17896/17895).

Attention: More information about the heaters

Please see the product descriptions for Autoterm Air 2D and Autoterm Air 4D for functions and features such as heating modes, high-altitude kit, etc. The heaters are used in our Hot Shower Kits exactly as described there and do not differ from the units sold individually.

Also read this article on the rationale behind the 2 × 2 kW heating-output set (Twin Kit), which contains many important insights for choosing the right heater size (Currently only available in German. Thank you for using your online translation tool).

Please select the appropriate heater (by heating output and system voltage) for your project in the dropdown menu.
 

The boiler – tigerexped & Autoterm combiBOIL

The new combiBOIL hot-water boiler is a product of unsurpassed quality, made in Western Europe, and the only boiler designed for use with an air heater that features an integrated thermostat in the versions with heating elements for 230/110 V operation. In the 12 V/24 V versions, integration of the thermostat is not possible due to space constraints – in this case, an external thermostat module is included with the boiler.
 

Fully integrated system

combiBOIL can be monitored and controlled via the Autoterm heater control panel: For the first time, the heater can automatically regulate the boiler temperature using the appropriate settings on the controller. The use of a manual diverter flap to bypass warm air around the boiler becomes unnecessary in the vast majority of applications. Overheating with dangerous steam formation in the boiler is effectively prevented. Only in cases of extremely high heating demand (e.g., arctic temperatures with suboptimal insulation) does a diverter flap still make sense.

An automatic frost protection mode can also be set on the control panel: If the water temperature drops to 2 °C, the heater automatically warms the water to +15 °C and the ambient air to +7 °C. For winter storage, of course, the water should be drained from the system; the boiler has its own drain valve for this. However, if the vehicle is left for a short period, this function can save you from having to make the entire system frost-proof with great effort – with the Hot Shower Kit 2.0 it is still effectively protected against frost damage.
 

Which size for how many people

The combiBOIL hot-water boiler is available with 7 l, 9 l and 12 l capacity. Our recommendation: 7 l is perfectly sufficient for two people. The water heated in the boiler can reach a temperature of up to 80 °C (depending on the heating method). By mixing in cold water as required, you end up with significantly more than 7 l of pleasantly warm shower water.

Bear in mind: More volume is not only an advantage. A larger boiler requires more installation space. Heat-up time also increases with higher volume, and heating – especially by electricity – consumes more energy. Finally, corresponding amounts of water must be carried and collected in a waste-water tank. An unnecessary „too much“ of power and volume quickly becomes a disadvantage.

We recommend the 9 l boiler from three people upwards, and the 12 l boiler from four people upwards.

You can find more details about the boiler here.

Please select the appropriate size for your project in the dropdown menu.

What else is included

The heater comes with installation kit and control panel:

• Heater unit(s) as selected (with 2 kW, 4 kW or 2 × 2 kW heating output for either 12 or 24 V system voltage)
• Plug-and-play wiring harness with AMP SuperSeal connectors
• Stainless-steel exhaust silencer (17 × 9 × 5 cm)
• Fuel pump
• Intake silencer (for the burner, not the warm air!)
• Fuel line
• Comprehensive assortment of small parts for installation
• Control panel Autoterm Comfort Boiler Control, which can control both the heater and the boiler. For all information on available heating modes, see Autoterm Comfort Control Standard.

You can find the detailed specifications of the available heaters in the product descriptions: Autoterm Air 2D with 2 kW / Air 4D with 4 kW.

• 1 × combiBOIL hot-water boiler with 7, 9 or 12 l capacity, with stainless-steel tank and heat exchanger

(You can find all specifications, dimensions and a detailed description here: combiBOIL hot-water boiler.)

Included for the warm-air ducting

• 2 × adjustable warm-air outlets
• 3 m warm-air ducting hose
• 2 × adapters for the boiler’s warm-air ports
• 1 × asymmetric Y-piece

Included for the water connection

1 × the hot-water connection kit (TEX1778) for a simple and safe integration of the boiler – also suitable for non-professionals. It minimizes the possibility of installation errors and their effects, so that the often most critical part of the water installation can be handled with ease. It consists of:

• 0.5 m blue special silicone drinking-water hose
• 1.0 m red special silicone drinking-water hose
• 1 × adjustable thermostatic mixing valve / scald protection
• 3 brass barbed fittings with male thread
• 2 brass barbed fittings with female thread (1 of these only included in the Hot Shower Kit)
• PTFE thread-seal tape
• 1 × straight hose connector
• 1 × T-piece for integration into the cold-water line
• 6 × stainless-steel hose clamps with clamping-jaw tightening
• 2 × smaller stainless-steel clamping-jaw clamps

What you additionally need (depending on your project)

Every vehicle is different, so we can’t just include certain items in the package. Depending on the situation and installation location, you must first choose what suits the respective land or water vehicle.

Heater bracket / installation flange

The heater can be installed without a bracket – but this is more complex and carries the risk that the hole pattern won’t fit exactly, stresses may occur, or heat won’t be dissipated properly. It is therefore usually advisable to use a bracket or our installation flange, which greatly simplifies mounting and provides good thermal decoupling at the same time.

The brackets come in different versions for various floor thicknesses or, for example, for installing the heater in a cockpit/stowage locker. For the Hot Shower Kit, one of these brackets is usually used; in the air-heater accessories you’ll also find brackets for other, special applications.

Water hoses

It’s similar with the plumbing hoses. Every vehicle is different; layouts and plans are individual. Calculate the length of hot- and cold-water hoses once you’ve fixed the installation positions for heater, boiler and all other components of the water system, and order accordingly.

Important: If you intend to use the water for drinking or cooking, we strongly recommend paying attention to the appropriate certification of the hoses. This ensures that no harmful substances leach into the drinking water and that taste and composition are not altered by the material.

Potable-water certified hoses for hot and cold water are available here.

In our range you’ll also find water filters for disinfection and safe drinking water at every destination. Our online magazine provides guidance to choosing the right filter (Currently only available in German. Thank you for using your online translation tool).

Pressure reducer

Our boiler tank is made of high-quality stainless steel and precisely manufactured. Nevertheless, the inlet pressure should be limited to 1.5 bar.

In all pressurized water systems and systems with submersible pumps with built-in or separate check valve, a pressure reducer should definitely be used upstream of the boiler, set to 1 to 1.5 bar. Under the following links you’ll find a pressure reducer with gauge and one without gauge.

A safety valve for releasing excessive pressure no longer needs to be purchased separately for the Hot Shower Kit 2.0 – combiBOIL has this factory-installed.

Water pump

A proper pump brings the system up to pressure and into circulation. It must be powerful enough to ensure a good, even flow even with water filtration and enable smooth operation of the water system. Durability and repairability assumed. You can get this pump and a suitable accumulator tank to make the operation of the pressurized water system even smoother and quieter as a bundle at a special price.